1. Field of the Invention
The present invention relates to an electrophotographic image forming process, an image forming apparatus which are capable of producing images at high speed and conserving energy and is highly suitable for operation over the long run.
2. Description of the Related Art
In a cooling and releasing process in an image-fixing process using a belt, if an electrophotographic image-receiving sheet is released from an image-fixing belt at a high temperature, offset occurs in which a toner-image-receiving layer and a toner layer remain on the surface of the belt. The resulting electrophotographic image-receiving sheet may often have decreased glossiness. In addition, the belt is stained and often invites decreased image quality in operation over the long run.
To solve these problems, Japanese Patent Application Laid-Open (JP-A) No. 05-2349 and JP-A No. 05-107960 propose a process for cooling a belt in a cooling and releasing process and the improvement on efficiency in such a process.
Specifically, JP-A No. 05-2349 discloses an image fixing apparatus having forced draft cooling means in a cooling section between a heating section and a releasing section so as to efficiently cool a film and a recording material concurrently.
JP-A No. 05-107960 discloses an endless belt image-fixing apparatus which has a cooling stabilizer and temperature control means and is capable of controlling the temperature.
JP-A No. 09-179421 proposes an image-fixing belt for an electrophotographic image forming apparatus, which image fixing belt comprises a belt substrate, an intermediate elastic layer having a specific thermal conductivity and being arranged on the substrate, and a surface elastic layer of a curable silicone rubber arranged on the intermediate elastic layer. This technique specifies the thermal conductivity of the belt member but does not take into consideration the heat capacities of the belt member, electrophotographic image-receiving sheet and toner which are actually to be cooled.
As thus described, conventional technologies do not sufficiently investigate the heat capacities of the belt member, electrophotographic image-receiving sheet, and toner to be cooled actually, and demands have been made on further improvements and development in this point.